我用anytree从文件生成一棵树， Tree.txt . 每个缩进是3个空格(

). 以下是我的文件的外观：

ROOT
   Node1
      Node2
         Node3
            Node4
   Node5
   Node6

以下是我到目前为止对生成代码的了解：

from anytree import Node, RenderTree, find_by_attr

def parse_tree():
    with open('Tree.txt', 'r') as file:
        file_contents = file.readlines()
        root = Node("ROOT")

        current_indent = -1 # store index for comparing later
        for (index, line) in enumerate(file_contents):

            leading_spaces = len(line) - len(line.lstrip(' '))
            indent = int(leading_spaces / 3) # indent = 3 spaces

            if indent > current_indent: # node must be 1 level down

                # get the previous Node (1 level up)
                previous_line = file_contents[index - 1].strip()
                current_line = line.strip()
                parent = find_by_attr(root, previous_line)
                Node(current_line, parent=parent) # start searching from top node (root) for `previous_line`
                current_indent = indent
            else: # node is on same level or higher
                print(f"What to do for {line.strip()}?") 
                # what should I do here?

        print(RenderTree(root)) # print the output

parse_tree()

但是，这会打印出：

What to do for Node5?
What to do for Node6?
Node('/ROOT')
└── Node('/ROOT/Node1')
    └── Node('/ROOT/Node1/Node2')
        └── Node('/ROOT/Node1/Node2/Node3')
            └── Node('/ROOT/Node1/Node2/Node3/Node4')

生成的树很好，但直到 Node4 - Node5 及 Node6 他们失踪了。这是意料之中的，因为我没有处理当前缩进小于前一缩进的情况（请参见 # what should I do here? ).
当当前缩进小于上一缩进时，我应该怎么做？我知道我需要上去 n 级别更高，但我如何确定这是哪个级别？